Difference Between LCD and LED Televisions

The LCD television is a flat-panel television which utilizes a Liquid Crystal Display technology. It has two layers of glass which are polarized and stuck together. The liquid crystals are held in one of the layers. These liquid crystals pass, or block the light, to produce images on the screen when the electric current passes through it.

However, the crystals do not produce their own light. The light comes from the series of fluorescent lamps at the back of the screen. There are millions of shutters arranged in a grid, which open and close to release and trap some of the light that is not needed to create images. Then each shutter is paired with a colored filter which produces a sub-pixel. These are so small, that when they combine, they create a single pixel, which appears to be a single spot of color on the screen. With the help of the fluorescent lamps, the images created by the liquid crystals become visible to the viewer.

LCD television produces high image quality. They can be made very thin, which makes them less space-consuming, and the user can hang them anywhere. This makes them appealing to buyers.

LED TV’s are actually very much like LCD TV’s. They also have a flat-screen which utilizes Liquid Crystal Display technology. The only difference is their source of light, which is at the back of the screen. The LCD TV uses fluorescent lamps, and the LED TV uses LED (Light Emitting Diodes).

There are two types of LED backlighting. One is referred to as Edge lighting, and the other is called Full-Array lighting. With the Edge lighting, the series of diodes are arranged along the outside edges of the screen. When there is power, the light is distributed across the screen. Alternatively, in Full-Array lighting, there are several rows of diodes behind the entire surface of the screen. They provide more control over brightness and dimming, because the diodes can be turned on and off independently.

LED TV’s are LCD TV’s with a new backlight system. They are newly developed for LCD’s, because Light Emitting Diodes are said to give more balance in color saturation, and use less power than the fluorescent lamps. LED TV’s are the newest version, and that’s why they are currently more expensive than the standard LCD TV’s.

Summary:

LED TV’s are still LCD TV’s. They are just considered to be the newer LCD TV version because of the new backlight system used. The LED TV uses Light Emitting Diodes, while the standard LCD TV uses fluorescent lamps. Although they both still use Liquid Crystal Display technology. The main difference is the part behind their screen, which is the backlight.

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Thanks for the Info. So that’s why. I bought an Sony LED TV last month and I was surprised in manual it was an LCD TV. I thought i was fooled but now it is making sense LED TV are LCD TV with LED backlights.

> The question is…what’s better for our world? I guess LED’s?
Lesser heat is lesser watts, or am i wrong?

You are not wrong. The first generation of LCD TVs used as much as a couple of hundred watts of electricity. Behind the LCD panel was a large florescent light, which often looked like a big bright spot that was annoyingly obvious behind the TV’s LCD panel.

You might have heard, even for general lighting, that florescents — such as the new spiral-shaped CFLs (compact florescent lights) — are already being replaced with LEDs for even better energy efficiency. Also, florescents have a spot of Mercury inside their tubes; multiplied by millions of CFLs, and that’s a bad pollution problem. I have never seen LEDs being named as a pollution hazard, at least not any worse than the general electronics entering the waste stream, but they certainly are not manufactured with mercury.

Anyway, back to power. At the moment, I’m using an old laptop and a 27″ LED monitor plugged into a power-usage meter. Together, they’re using 65 watts. I have measured the 27″ LED display using 25 watts by itself at normal brightness. Better than LCD’s 100 to 200 watt consumption.

PS: My power usage meter is a Kill-O-Watt Meter. Search Amazon for item # B00009MDBU The price keeps going up and down; I wouldn’t spend too much more than $25 for one of these. Read the reviews for usage pointers.

Turns out I was a bit of on those numbers. It was the 29″ NEC 1024×768 display that was using 200-250 watts. The Mitsubishi Megaview uses 255 to 350 watts, depending on how much white is on the screen. I custom built a stand for it and it weighs about 200lbs. My bro and I lifted it up there. It turns 20 this year and still working fine. Hopefully 4k OLED is cheap by the time the thing fails.

I wish they would quit calling them “LED” TVs. They aren’t, and there are actual true LED TVs out there. Those signs you see outside of businesses…those are LEDs, true LED where there is no LCD and each pixel does all the lighting.

Yeh, the first generation of those LCD TVs was a long time ago, but I remember being surprised and frustrated at how much power they used. One trick I had was to go into a store that sells lots of TVs and put my hand over the back of each one to see which ones were giving off less heat.

(The other test was to see which display didn’t show a big bright spot in the middle of the screen from the florescent light inside, a problem that LED TVs don’t have.)

There was more frustration trying to find current-draw specs on the TVs. Sometimes, even going to the manufacturers’ website wouldn’t help uncover the desired data.

I found one, it’s a 55″ LCD TV, which is a little bigger than what I wanted to use as an example, but. Search Newegg for item # 9SIA9563GP9161 , it’s a “Vizio 55″ Class (54.64″ Diag.) 1080p 120Hz LCD HDTV VF550M” In the specifications, it says is uses 244 watts average.

I can see you getting the Kill-O-Watt especially for the CRT TV, especially 37″. It sounds like a thing of beauty, but your inquiring mind wanted to know how much power it uses.

I also remember when a few hundred dollars was a lot to spend on a CRT TV. And then when the LCDs came out, they were a few hundred dollars or even more, and it was hard to justify getting rid of Big Beauty. The LCD’s best selling point was that you get a lot more picture for the same power usage, assuming you got a model that had a good picture.

Here’s a 55″ inch LED Vizio for comparison, Newegg item # N82E16889262406 . They provide specifications, and they say it’s 59.3W(!). “Power Consumption: 59.3W Standby Power Consumption: <0.5W" Not 59.4, not 59.2., but "59.3." See the significant figures. Feel the significant figures. Love the significant figures. Send an email to the FTC about there being too many significant figures.

The takeaway is that there are still TVs on the market that use a lot of power and generate a lot of heat and electricity bills, and that might not be desirable for some people, so Power Consumption should be taken into consideration.

More recently, I read a comment that LCD TVs have better color saturation than LEDs. It's something to research, but I wouldn't get disillusioned about LEDs because of it.

The plummet in LCD prices took a very long time to happen, dramatic drops didn't happen until the last year or two. Probably will be even more drops on great 1080 LEDs now that 4k TVs have arrived and they're trying to push them, now.

Also, the 55" Vizo LED (which I pulled out of a hat without doing any comparison shopping) costs $639. (Not $638…) For 55", it wasn't too long ago it would have cost over $2000. Granted, if our brains are calibrated in 1995-dollars, $639 will still seem like an absurd amount of money to spend for a TV. Of course, 1995 is getting to be a long time ago.

When the time comes to move your 37" TV, call a moving company and ask for a couple of strong guys to help. It's not worth the hernia, and the arthroscopic surgery, etc.

Then I did Google-Images, and saw that LFDs are video displays that are large enough to cover the sides of buildings.

One technology being used for LFD is “Laser Phosphor Display,” which I’ve never seen being used for consumer equipment. I did not research what other technologies are being used for LFD.

The thing with LEDs, as you know, is that you can get a very fine resolution so that you can’t see the individual pixels even if you’re sitting as close as a couple of feet from the display. For a display that’s as big as the side of a building, no one is going to be a couple of feet from the display — 50 feet might be the ‘minimum,’ so the individual pixels can be bigger and farther from each other, but will look fine from over 50 feet away. It would be wasteful to use LEDs to cover the side of a building because from over 50 feet away, a large-format technology already looks good, and increased resolution would not result in any increased perceived image quality.

With Laser Phosphor technology, you’re shooting a laser at a phosphor screen, similar to old CRT glass picture tubes where an electron-beam is shot at a layer of phosphor inside the glass tube. But using a laser, the laser can be so powerful that it creates a very bright picture that can light up a whole street at night. So, LFDs have less resolution than LEDs, but are a whole lot brighter.

So, the sizes of LFDs and LCDs are of different magnitudes (home use vs. gigantic), and they use different technologies each with their own advantages and disadvantages that make them suitable for different applications.

I did recently hear of an LED screen that was over 100 inches diagonal, but that’s still not big enough to cover a whole side of a building.

led is actually a misnomer. the pixels themselves don’t emit any light but the red/green/blue liquid crystals get turned on (to pass light through) in proportion to the applied electric potential (as per the picture light strength and color). they let the backlit ‘led’s light to pass through each of them (r/g/b) according to the picture element hue and saturation, thus reproducing the picture correctly.

but the latest entrant to the flat screens is the oled or organic light emitting diode. these were first popularized by samsung/lg using their own proprietary names (qled – samsung, oled – lg). later variants such as qdled, amoled, microled &c developed, enhancing the earlier technology. samsung and lg first used these in their cellular phones.

in the cfl/led flat screens, the whole crystal matrix will be lit up to an extent somewhat, because the cfls/leds all light up simultaneously and only the hue/saturation of the color pixel controls what color is seen. if the pixel is white, the whole brightness of the backlight passes through. if it is any color only that portion of color is shown. if it’s black, no color shows, but as the backlight is lit up, it shows up as a partial brightness of the liquid crystal. thus, the view is spoilt to a large extent when a dark background is to be shown as we still see a bright white patch of light all through the display.

in the oled televisions, each pixel has its own backlight in the form of an inorganic nanoparticle, which would emit light when and only when the pixel in its front gets excited on passage of electric potential. when the pixel is dark (black or darkest shades), the dot backlight won’t emit any light. this technology is truly marvelus as you don’t see any white patch of light throughout the display because there isn’t any led/cfl that lits up whole. so each pixel shows up as a ‘true’ color because there isn’t any white or off-white light to interfere its color emission. hence, colors show up in their true nature (as what the camera captures) as opposed to an extent of color saturation/dilution that liquid crystal displays suffer from.

i’m not a technology expert and i’ve only outlined the major feature of oled televisions as per what i’ve come to understand the principle behind the technology. on a personal note, i couldn’t believe my eyes when i saw a qdled/oled television displaying the same movie as an led-lcd. the led-lcd suffered from a over display of white patch that spoiled the 4k nature documentary of a dark cave in a dense forest. the cave still showed up as a black boundary with whiter inside. however, on the qdled/oled, the cave looked just as it should: pitch black. that made the movie truly pleasing to watch.

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Written by : Ian F.
and updated on September 5, 2011

Articles on DifferenceBetween.net are general information, and are not intended to substitute for professional advice. The information is "AS IS", "WITH ALL FAULTS". User assumes all risk of use, damage, or injury. You agree that we have no liability for any damages.
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